1. Field of the Invention
The present invention relates to a retaining piece of a ball valve. More particularly to a retaining piece having groove to provide resilience such that a ball of the ball valve is able to be tightly sealed between the retaining pieces so as to prevent leakage of the ball valve.
2. Description of Related Art
In many applications, especially in industrial processes, ball valves are used to control the flow of a fluid through piping. With reference to FIG. 3, a conventional ball valve (50) is shown and has a hollow seat (51) with two side-openings, a ball (52) rotatably received inside the hollow seat (51), and two retaining pieces (53) oppositely disposed to sandwich the ball (52). A spindle (541) is coupled to the ball (52) and extends through a spindle hole (511) defined through a top portion of the hollow seat (51). The spindle (541) is further couple to a handle (54) such that the rotation of the ball (52) received inside the hollow seat (51) is able to be controlled by the handle (54). A passage (521) transversely defined through the ball (52) so that when the ball (52) is rotated to a position such that the passage (521) communicates with the two side-openings, fluid is able to flow through the ball valve from one of the two side-openings to the other side-opening via the passage (521). The flow rate of the fluid is able to be controlled or completely shut down by turning the handle (54) to control the communication of the side-openings and the passage (521). However, leakage of the ball valve typically happens when the engagement between the ball (52) and the retaining piece (53) is not tightly sealed. Especially when after long term use of the ball valve, the inevitable rubbing between the surface of the ball (52) and the surface of the retaining piece (53) gradually causes the ball (52) and the retaining pieces (52) to lose their sealing engagement and therefore resulting in the leakage of the ball valve.
With reference to FIG. 4, an improved retaining piece (63) is invented to overcome the aforementioned leaking problem. The retaining piece (63) is fitted with a metallic ring (631) which is attached to a side of the retaining piece (63) opposite to the side having the ball (52) securely engaged. A space is provided between the retaining piece (63) and the metallic ring (631) to provide resilience. With the metallic ring (631) added, the retaining pieces (63) cushion yet firmly engage the ball (52) therebetween such that even though rubbing between the ball (52) and the retaining pieces (63) is still inevitable, the resilience provided is able to automatically adjust and keep the ball (52) tightly sealed with the retaining pieces (63) to prevent the leakage of the ball valve. Nevertheless, although the retaining piece (63) with the metallic ring (631) tends to solve the leakage problem, a further problem may rise in that adding the retaining piece (63) complicates the structure of the ball valve which in turn increases of the costs associated with the manufacturing of the ball valve.
To overcome the shortcomings, the present invention tends to provide a retaining piece of a ball valve to mitigate or obviate the aforementioned problems.
The objective of the present invention is to provide a retaining piece of a ball valve. A groove is defined in and around the retaining piece to provide resilience so that the retaining piece is able to tightly engage with a ball of the ball valve, and thereby prevent leakage of the ball valve.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.